What does $(( )) signify in Bash?

In Bash, $(( )) is used for arithmetic expansion. It allows you to perform arithmetic operations and evaluate expressions within the parentheses. The result of the expression is returned as an integer.

Example:

result=$(( 5 + 3 ))
echo $result  # Output: 8

You can use various arithmetic operators such as +, -, *, /, and % within the $(( )) syntax.